The present invention relates to apparatus for binding the boot of a skier to the surface of a ski. More particularly, the present invention relates to ski binding apparatus which can be used for either downhill or cross-country usage. The present invention is particularly useful for providing a single common ski binding structure which can be easily converted so that the boot or shoe of a skier is appropriately secured to the ski surface for any of the typical environments encountered by skiers.
Because of conflicting requirements, ski bindings and harness developments of the past have generally been directed to utilization either in downhill skiing or cross-country skiing. For cross-country or touring usage, the mechanism for restraining the ski boot relative to the skiing surface must be capable of vertical pivoting to accommodate a walking type motion while securely retaining the boot to the ski. Conversely, ski bindings for downhill use should not allow any vertical motion of the boot but should include means for permitting a horizontally lateral release movement to reduce the hazard of injury to the skier particularly in a fall. However, such horizontally lateral release devices are undesirable when the skier is traversing in a cross-country mode. That is, a binding as developed for downhill use must firmly hold the skier's boot on the ski in a fixed position to give the skier control of his skis. Conversely, cross-country use requires allowance for raising of the boot heel to a near vertical position as the skier strides forward while skiing cross-country. Accordingly, any ski binding which is to be used for both downhill and cross-country must allow the skier to quickly and reliably shift the mechanism so as either to retain the heel in fixed position on the ski but with potential lateral release or to a mode wherein the heel is allowed to raise from the ski but not permit it to pivot on the ski surface as would be effected by an operable lateral release mechanism.
Although predating confined slope downhill skiing, ski touring or cross-country skiing has drawn increased attention recently particularly since it represents a pleasurable and inexpensive recreational sport. However, even when cross-country skiing, a considerable portion of such tours are engaged in downhill skiing. Accordingly, the ski binding must be selectively convertible to accommodate the walking motion as involved in traversing terrains and also downhill skiing. Furthermore, since the cross-country skier is frequently in isolated areas, it is imperative that the ski binding mechanism be as reliable as possible and have minimal mechanical failure hazard. Still further, it is imperative that any failure which does occur be easily repaired and not require special tools or components. Skiers and the ski industry have long recognized the need for a versatile binding which is of minimal and simplified mechanical structure and which is further lightweight, and durable but reliably releasable when required.
Several approaches have been taken in the prior art to resolve the problem of converting a ski binding between downhill and cross-country use. For instance, some devices have been employed which will permit bending of the boot or restrain its bending as in U.S. Pat. No. 1,964,103 by Attenhofer. A somewhat similar approach except employing a bracket which can be pivoted or clamped against pivoting is shown in Taft U.S. Pat. No. 2,172,669. Since such devices do not provide secure retention of the boot heel against the ski surface, other devices have been developed to resolve this problem by using flexible plates for underlying the boot with the plate hinged at the toe and including means for selectively restraining the plate from pivoting. Examples are Hilding U.S. Pat. No. 2,649,306, Reuge U.S. Pat. No. 2,600,688, Berlenbach U.S. Pat. No. 2,698,757, Jones U.S. Pat. No. 2,831,696 and Weckeiser U.S. Pat. No. 3,877,712. Shimizu U.S. Pat. No. 2,764,418 has suggested an arrangement for avoiding the use of a separate hinge or flexible plate by employing a special arrangement of restraining collar and cable harness structure. In Shimizu, a cable hold-down hook arrangement is employed to selectably hold the boot in its flat position or can be released so as to permit flexing with the boot being retained in position by the special harness thereof. Other bindings intended for convertible use are the so-called Silveretta of German manufacture and the Ramy Securus bindings of French design.
Although a binding as shown by the above-mentioned Hilding patent is of relatively simple mechanical structure, it suffers from several disadvantages. For instance, the ski boot must be permanently attached to the hinged plate which thus makes it unavailable for use separate from the ski and further prevents the lateral release required for preventing injury. Similar disadvantages are associated with the semi-permanent attachment structure such as that shown by Taft, Berlenbach and Weckeiser.
It is preferable to use a stiff or semi-flexible soled boot when skiing with a combination binding. This is true since the boot, when clamped tightly to the ski for downhill use, must not buckle as with a soft-soled boot in order to allow the skier to control his skis. However, apparatus such as Taft, Shimizu and possibly Berlenbach employ soft-soled boots thus rendering these bindings inferior for downhill use. Furthermore, the utilization of complex mechanisms to obtain the combination status as with the Ramy Seccurus, Berlenbach patent, Jones patent and Weckeiser patent is likewise undesirable. Such complex mechanisms increase the probability of damage or breakage of components which is especially undesirable when in an isolated area thereby stranding the user.
Accordingly, despite the longstanding recognition of the problems associated with converting ski bindings between downhill and cross-country uses, there has been a continuing need for a ski binding which employs minimal lightweight but durable structure elements, which can be quickly converted between a downhill mode and a cross-country mode in the field, which establishes a secure retention of the boot sole relative to the ski surface while allowing lateral release for injury prevention as in downhill utilizations but which further permits maximum vertical flexure with no lateral release as required for the walking motion of cross-country usage.